1. Field of the Invention
This invention relates to tube benders and in particular to manually operable tube benders wherein a forming member is swung about a mandrel bending axis by means of a handle associated therewith and a handle mounted to the mandrel.
2. DESCRIPTION OF THE BACKGROUND ART
Manually operable tube benders are well known in the art. One improved form of such tube bender is illustrated in U.S. Pat. No. 2,796,785 of Howard L. Philippe. As shown therein, a shoe forming member is provided with a handle. The shoe is swingably mounted to a mandrel for pivotal movement about a bending axis. A second handle is connected to the mandrel. A hook is swingably mounted on the second handle for engaging the tube at a point adjacent the bend start point of a groove in the periphery of the mandrel into which the tube is urged in the bending operation.
Further improved tube benders are illustrated in U.S. Pat. No. 2,887,917 and 3,926,028 of Leonard J. Kowal. In U.S. Pat. No. 2,887,917, a tube bender is illustrated wherein the handle connected to the mandrel is provided with an offset and improved scale means are provided on the mandrel for indicating the extent of the formed bend.
In Kowal U.S. Pat. No. 3,926,028, the tube bender is provided with a vise mounting portion in lieu of the handle secured to the mandrel. In one form, the hook is formed integrally with the male clamp portion, and in a second form, the hook is pivotally mounted thereon.
In U.S. Pat. No. 3,750,447 of Leonard J. Kowal and William R. Saddler, a further improved tube bender is illustrated having fixed hook means with a cutout space being provided in confrontation to the hook to permit facilitated installation of the tube to be bent into the tool, notwithstanding the fixed relationship of the hook to the mandrel.